cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A130853 Runs of 1's of lengths 1, Fibonacci numbers F(1), F(2), F(3), ... (A000045) separated by 0's.

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%I A130853 #45 May 22 2025 01:03:19
%S A130853 0,1,0,1,0,1,1,0,1,1,1,0,1,1,1,1,1,0,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1,
%T A130853 1,1,1,1,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,
%U A130853 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1
%N A130853 Runs of 1's of lengths 1, Fibonacci numbers F(1), F(2), F(3), ... (A000045) separated by 0's.
%C A130853 Might be called a Fibonacci message.
%H A130853 Antti Karttunen, <a href="/A130853/b130853.txt">Table of n, a(n) for n = 1..46390</a>
%H A130853 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%F A130853 a(n) = b(n+1) - b(n) where b(n) = round(LambertW((phi^(3/2 + n)*log(phi))/sqrt(5)) / log(phi)), phi = (1 + sqrt(5))/2. - _Alan Michael Gómez Calderón_, Dec 11 2024
%e A130853 Begin with 0. First Fibonacci number F(1)=1, so append 1's to 0 once - 01, append 0 - 010, F(2)=1, append 1's once and 0 - 01010, F(3)=2, we append two 1's and 0 - 01010110, ...
%e A130853 As a triangle:
%e A130853   0, 1;
%e A130853   0, 1;
%e A130853   0, 1, 1;
%e A130853   0, 1, 1, 1;
%e A130853   0, 1, 1, 1, 1, 1;
%e A130853   0, 1, 1, 1, 1, 1, 1, 1, 1;
%e A130853   0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e A130853   0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
%e A130853   ...
%p A130853 ts_Finonacci_zap:=proc(n) local i,j,tren,ans; ans := [ 0 ]: for i from 1 to n do tren := combinat[fibonacci](i): for j from 1 to tren do ans:=[ op(ans), 1 ]: od: ans:=[ op(ans), 0 ]: od; RETURN(ans) end: ts_Finonacci_zap(16);
%p A130853 # second Maple program:
%p A130853 T:= n-> [0,1$(<<0|1>, <1|1>>^n)[1,2]][]:
%p A130853 seq(T(n), n=1..10);  # _Alois P. Heinz_, Dec 11 2024
%t A130853 T[n_] := Join[{0}, Table[1, MatrixPower[{{0, 1}, {1, 1}}, n][[1, 2]]]];
%t A130853 Table[T[n], {n, 1, 10}] // Flatten (* _Jean-François Alcover_, May 21 2025, after _Alois P. Heinz_ *)
%o A130853 (PARI) { n=0; i=0; while(n<22, n++; i++; write("b130853.txt", i, " ", 0); k = fibonacci(n); while(k>0, i++; k--; write("b130853.txt", i, " ", 1))); }; \\ _Antti Karttunen_, Dec 07 2017
%Y A130853 Cf. A000045, A093521, A232896 (the positions of zeros).
%Y A130853 Cf. A001622, A003849, A005614, A194029.
%K A130853 nonn,tabf
%O A130853 1,1
%A A130853 _Jani Melik_, Jul 21 2007